46 lines
1.0 KiB
C
46 lines
1.0 KiB
C
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/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* A user-space bitmap wrapper to provide a subset of kernel bitmap operations.
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*
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* Most functions are not a direct copy of the kernel version, but should be
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* good enough for single thread usage.
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*/
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#ifndef _BTRFS_PROGS_LINUX_BITMAP_H_
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#define _BTRFS_PROGS_LINUX_BITMAP_H_
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#include <stdlib.h>
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#include "kerncompat.h"
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#include "kernel-lib/bitops.h"
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static inline unsigned long *bitmap_zalloc(unsigned int nbits)
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{
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return calloc(BITS_TO_LONGS(nbits), BITS_PER_LONG);
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}
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static inline void bitmap_free(unsigned long *bitmap)
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{
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free(bitmap);
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}
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#define BITMAP_LAST_WORK_MASK(nbits) (~0ULL >> (-(nbits) & (BITS_PER_LONG - 1)))
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static inline unsigned int bitmap_weight(const unsigned long *bitmap, unsigned int nbits)
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{
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int ret = 0;
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int i;
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/* Handle the aligned part first. */
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for (i = 0; i < nbits / BITS_PER_LONG; i++)
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ret += hweight_long(bitmap[i]);
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/* The remaining unaligned part. */
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if (nbits % BITS_PER_LONG)
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ret += bitmap[i] & BITMAP_LAST_WORD_MASK(nbits);
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return ret;
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}
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#endif
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